1. B,c
2. A,d
3. A,c
4. D
5. B
6. B
7. A,b
8. C
9. A
10. C
11. C
12. D
13. A,d
14. C
15. A,c
16. B
17. B
18. A,d
19. C
20. B,c,d
Electrical circuit- a path in which electrons from a voltage or current source flow.
Frequency - the number of occurrences of a repeating event per unit time.
Amplitude - The amplitude of a periodic variable is a measure of its change over a single period
Phase - With appropriate circuitry, peak-to-peak amplitudes of electric oscillations can be measured by meters or by viewing the waveform on an oscilloscope.
Bit time - It is defined as the time it takes for one bit to be ejected from a Network Interface Card (NIC) operating at some predefined standard speed, such as 10 Mbit/s.
Encoding scheme - consists of a code that pairs each character from a given repertoire with something else—such as a bit pattern, sequence of natural numbers, octets, or electrical pulses—in order to facilitate the transmission of data (generally numbers or text) through telecommunication networks or for data storage
UTP - Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources.
Core - The core of a conventional optical fiber is a cylinder of glass or plastic that runs along the fiber's length.

Cladding - Cladding is one or more layers of materials of lower refractive index
Radio waves - are a type of